Weed Information: Persicaria lapathifolia (smartweed, pale)
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Persicaria lapathifolia (smartweed, pale)

Family: Polygonaceae

Description

Annual weeds, usually erect, with swollen nodes. Common in moist, cultivated soils. The sheathing stipules, which are typical of the genus, are ciliate margined, glabrous and prominent at the base of the leaves, which are 5 to 20 cm long. In Common Weeds of Canada the photos on pages 26 and 27 are switched.

Characteristics

Flower Color
  • Red (or pink)
  • Green
  • White
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary cluster
  • Axillary racemes
  • Axillary spikes
  • Panicle
  • Terminal raceme
  • Terminal spike
Number of Petals
  • 0 (no petals)
  • 5 petals
Petal Separation
  • Completely free to base
  • United at base only (<25% length)
Petal Tip
  • Rounded
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 1 mm (.04 inch)
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Flower Width (Head width in the Asteraceae)
  • 1 mm (.04 inch)
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Number of Sepals
  • sepals lacking
  • 4 sepals
  • 5 sepals
Sepal Separation
  • United at base < 25% length
Sepal Tip
  • Rounded
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 2 styles
  • 3 styles
Number of Stamens
  • 8 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 2 carpels
  • 3 carpels
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Achene
Fruit Length at Maturity
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Fruit Width at Maturity
  • 1 mm (.04 inch) or less
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
Leaf Type
  • Simple (including lobed leaves)
Stipules
  • Membranous, entire
  • Membranous, laciniate
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole < 25% total length
Leaf Length (blade PLUS petiole)
  • 4 - 10 cm (1.60 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
Leaf Width
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.6 inches)
  • 4 - 10 cm (1.6 - 4.0 inches)
Leaf Shape (simple leaves only)
  • Elliptic
  • Lanceolate
  • Linear or filiform
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Acuminate (attenuate)
Leaf or Leaflet Tip
  • Acute
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Pubescent
Succulence
  • Not succulent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Annual
Growth Habit (while flowering)
  • Erect, columnar (narrow)
Plant Height at Maturity
  • 2 - 4 dm (8.0 - 16.0 inches)
  • 4 - 6 dm (1.3 - 2.0 feet)
  • 6 - 8 dm (2.0 - 2.6 feet)
  • 8 - 10 dm (2.6 - 3.3 feet)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Aquatic
  • Semi-aquatic
  • Seasonally saturated
Chlorophyll
  • Present

Stem Cross Section
  • Round
Flowering Stem Leaves
  • Stem leaves greatly reduced
  • Stem uniformly leafy
Main Stem Branches
  • Main stem unbranched
  • Main stem branched

Root or Vegetative Propagule
  • Tap Root

US State
  • Alabama
  • Arkansas
  • Connecticut
  • Delaware
  • Florida
  • Georgia
  • Illinois
  • Kansas
  • Kentucky
  • Louisiana
  • Massachusetts
  • Maine
  • Michigan
  • Missouri
  • Mississippi
  • North Carolina
  • New Hampshire
  • New Jersey
  • New York
  • Ohio
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • Wisconsin
  • West Virginia
  • Indiana
  • Maryland
  • Rhode Island
  • Vermont
  • Alaska
  • Arizona
  • California
  • Colorado
  • Iowa
  • Idaho
  • Minnesota
  • Montana
  • North Dakota
  • New Mexico
  • Nevada
  • Oklahoma
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
  • Nebraska
Canadian Province or Territory
  • British Columbia
  • New Brunswick
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Alberta
  • Manitoba
  • Newfoundland
  • Saskatchewan
  • Yukon
  • Northwest Territory
Other
  • District of Columbia
  • St. Pierre and Miquelon
  • Labrador
  • Greenland

  • Aquatic and Riparian Plants of the West, 2003 (ISBN# 1-879906-59-7) See page: 314
  • California Growers Weed Identification Handbook, 1968 - 1998 University of California Publication # 4030-1, See page: 177
  • Common Weeds of Canada, Mulligan 1987 (ISBN 0-910053-59-9) See page: 25, 26
  • Garden Weeds of Southern California, 1981, See page: 26
  • How to Know the Weeds, 1972, (ISBN# 0-697-04880-2) See page: 56
  • Identification Guide to the Weeds of Quebec, 1999 (ISBN# 2-89457-174-7) See page: 134
  • Manual of Ohio Weeds, 1931 Ohio Ag. Exp. Station Bull. # 475, See page: 58
  • Northwest Weeds, 1990 (ISBN 0-87842-249-8) See page: 31
  • Ontario Weeds, 1992 Agdex 640, Publication #505 See page: 54
  • South Dakota Weeds, 1967 South Dakota State University, See page: 75
  • South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 70
  • S.W.S.S. Weed ID Guide, 1993 Section Number and Five letter code: 6 POLLA
  • Weed Seeds of the Great Plains, 1993 University of Kansas# 92-125-B ISBN# 0-7006-0651-3 See index #: 39
  • Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 169
  • Weeds, A Golden Guide, 1972 ISBN#0-307-24353-2 See page: 41, 42
  • Weeds and Poisonous Plants of Wyoming and Utah 1987 (ISBN 0-941570-06-1) See page: 14
  • Weeds of Alberta, 1983 Alberta Environmental Centre Agdex 640-4, See page: 27
  • Weeds of California, 1970, State of California Publications and Documents. See page: 137
  • Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 1319
  • Weeds of Canada, 1970 Canada Dept. of Ag., Pub. # 948, See page: 40
  • Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 480
  • Weeds of Nova Scotia, 1986 (ISBN# 0-88871-063) See page: 48
  • Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 262
  • Weeds of the Northeast, 1956, Univ. of Delaware Field Manual #1 See species #: 116
  • Weeds of the Northern United States and Canada, 1964 Montgomery See page: 31
  • Weeds of the Northern U.S, and Canada, 1999 Royer and Dickinson, (ISBN# 1-55105-221-0) See page: 90 - 91
  • Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 259
  • Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 511
  • Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 506
  • Weeds of Utah, 1971 UAES Special Report 21, See page: 25
  • Listed as a `Weed` by the Biota of North America Program, 2008 x
  • Listed in the WSSA Composite List of Weeds X
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